With the development of display technology, liquid crystal display devices have become the most common display devices.
In the meanwhile, with the popularization of smart electronic products, capacitive touch screens are also widely used in electronic products, such as cell phones, tablet PCs, etc. Currently, capacitive touch screens mainly adopt one glass solution (OGS), on-cell, and in-cell technologies. Compared with OGS and on-cell technologies, in-cell technology is superior in production process, and products using it are thinner and lighter, more transparent, and more stable in structure.
As shown in FIG. 1, a liquid crystal display device adopting in-cell technology comprises a plurality of common electrodes 1 and a plurality of address lines 2. Each of the common electrodes 1 is connected to a drive circuit 3 with one address line 2. When an image is displayed, the common electrode 1 is connected to a common voltage output end in the drive circuit 3 through the address line 2. When a touch scan is performed, the common electrode 1 is connected to a touch signal processor in the drive circuit 3 through the address line 2.
The existing technologies have at least the following problems. In order to obtain an in-cell touch screen, it is necessary to provide an array substrate additionally with at least a third metal layer (namely address lines), and an insulating layer between the third metal layer and another conductor layer. Therefore, in the process of manufacturing the array substrate, it is required to add at least one photo engraving process (PEP), which renders the process of manufacturing the array substrate too complex.